Lubricant containing beta-ketols

ABSTRACT

A LUBRICANT COMPOSITION COMPRISING A MAJOR PORTION OF A CARRIER FLUID AND A MINOR EFFECTIVE PORTION OF A B-KETOL OF FROM 11 TO 40 CARBONS ATOMS CONTAINING AN ALKYL GROUP OF FROM 8 TO 30 CARBON ATOMS IN CHAIN LENGTH.

United States Patent Olfice 3,649,537 LUBRICANT CONTAINING B-KETOLS Bruce W. Hotten, Orinda, Califl, assignor to Chevron Research Company, San Francisco, Calif. N Drawing. Filed July 1, 1970, Ser. No. 51,705 Int. Cl. C16m 1/20, 1/22 U.S. Cl. 252-495 8 Claims ABSTRACT OF THE DISCLOSURE A lubricant composition comprising a major portion of a carrier fluid and a minor effective portion of a B-ketol of from 11 to 40 carbons atoms containing an alkyl group of from 8 to 30 carbon atoms in chain length.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to the use of B-ketols as components of lubricants.

In the past, the lubrication of aluminum surfaces has been considered a serious problem. Aluminum normally requires lubrication during rolling of aluminum sheets or foil, machining of aluminum parts, and mechanical operation of aluminum parts in contact with each other or with other metal surfaces. The high wear rate and galling tendency of aluminum have restricted its development in severly treated mechanical parts such as unlined engine blocks.

Attempts to lubricate aluminum surfaces in the past have generally involved the use of lubricants found satisfactory for iron and steel systems. These have, however, proved relatively unsatisfactory for the lubrication of aluminum. Many did not adequately lubricate the aluminum surfaces and decrease the galling or wearing, and some stained the aluminum surface so that the metal no longer had the clean appearance desired with aluminum.

It would, therefore, be desirable to provide a lubricant capable of adequately lubricating an aluminum surface and reducing the wear and galling of the aluminum. Where final appearance of the aluminum surface is important, it would also be desirable to have a lubricant which would not stain the aluminum surface. Finally, it would also be desirable for such lubricant to have the ability to lubricate metal surfaces other than aluminum.

Description of the prior art US. Pat. 2,670,382, abstracted in volume 49 of Chemical Abstracts at column 4020 g. discloses 3-npentadecyl-6acetyl phenol, as well as several 2-hydroxyphenones having alkyl substituents of less than 10 carbon atoms on the benzene ring. These materials are intermediates in the production of sulfurized rubber age resistors. US. Pat. 2,221,380 discloses the use of acetophenone as a sludge-dispersant in a crankcase lubricating oil. Polyketones in lubricating oils are disclosed in US. Pat. 2,315,063. A number of aromatic compounds containing both hydroxyl and carbonyl groups are disclosed as useful for radiation protection in volume 50 of Chemical Abstracts, at column 5624h. The use of diols in aluminum lubricants is disclosed in US. patent applica tions Ser. Nos. 853,474, filed Aug. 27, 1969 now abandoned, and 888,806, filed Dec. 29, 1969.

SUMMARY This invention is a lubricant composition capable of coordinating with a metal surface which composition comprises a major portion of a carrier fluid and a minor efiective portion of a fl-ketol of from 11 to 40 carbon 3,649,537 Patented Mar. 14, 1972 DETAILED DESCRIPTION OF THE INVENTION In its broadest form, this invention is a lubricant composition capable of coordinating with a metal surface which composition comprises a major portion of a carrier fiuid and a minor effective portion of a fl-ketol of from 11 to 40 carbon atoms containing an alkyl group of from 8 to 30 carbon atoms in chain length.

The ,B-ketols used in the composition of this invention contain two principal functional groups. The first group is the fl-ketol group itself, which comprises a hydroxyl radical and a carbonyl radicals, the carbon atoms of which are joined through a single, common, intermediate carbon atom. It is this functional group which provides coordination with the metal surface and causes the fi-ketol to act as a boundary lubricant to protect the metal. Coordination, as used herein, refers to the formation of a chelate ring in which the hydroxyl oxygen forms an alkoxide bond with a metal atom of the metal surface, and the carbonyl oxygen forms a coordinate bond with the same metal atom. The chelate ring thus contains a metal atom, two oxygen atoms, and three carbon atoms. The ability of the 18-ketol to coordinate with the metal surface is an integral part of this invention, for lubricants which do not coordinate with the metal surface have been found to be poor aluminum lubricants.

The second functional group which characterizes the fl-ketol used in the lubricant of this invention is an alkyl group of from 8 to 30 carbon atoms in chain length. This group may be attached directly to one carbon atom of the e-ketol group, or may be attached to the B-ketol group indirectly through an aromatic structure. The chain referred to is a linear arrangement of 8 to 30 carbon atoms. The chain may have pendant hydrocarbon radicals attached to it, but the carbon atoms in these pendant radicals are not considered when determining the length of the chain. Neither are the three carbon atoms of the ,G-ketol group counted as part of the alkyl chain in determining the latters length.

The [i-ketols useful in this invention may be divided into two classes: (1) alkyl and alkaryl fl-ketols, and (2) alkyl-substituted 2-alkanolyphenols. The former will have the following structure:

wherein R R and R are each hydrogen, alkyl of from 1 to 30 carbon atoms, or alkaryl of from 7 to 30 carbon atoms, and R is alkyl of from 1 to 30 carbon atoms, or alkaryl of from 7 to 30 carbon atoms. One of the four R groups must contain the C -C linear alkyl carbon chain described above. It is preferred that each of the three R groups not containing the C -C carbon chain be hydrogen or a lower alkyl; i.e., C C or, preferably, C -C alkyl, in order to minimize steric hindrance of the p-ketol function. It is recognized that there are some compounds which nominally conform to the above formula, but which contain R substituents which sterically hinder the B-ketol function. However, since it is required that the S-ketol be able to coordinate with the metal surface, these sterically hindered compounds which cannot coordinate are excluded from the scope of this invention.

The second class of B-ketols, the alkyl-substituted 2- alkanoylphenols, will have the following formula:

wherein R is a single alkyl substituent containing a linear chain of from 8 to 30 carbon atoms, and R is an alkyl group of from 1 to 7, preferably 1 to 3, carbon atoms. The phenol portion of the molecule may also be substituted with up to three additional carbon atoms arranged in one or two side chains on the benzene ring; i.e., the term phenyl as used herein also includes cresol, xylenol, phlorol, cumenol, and the like in their various ortho-, meta-, and para-configurations.

The B-ketols will each have a total of from 11 to 40 carbon atoms. The C C linear carbon chain will preferably be of from 12 to 24 carbon atoms.

The (I -C alkyl chain on the alkyl B-ketols will preferably be unsubstituted or substituted with one or two lower (i.e., C -C alkyl groups. The alkyl chain on the alkaryl /3-ketols or alkyl-substituted 2-alkanoylphenols will preferably be a l-methyl secondary alkyl group. (In this case the methyl group is not included in counting the required 8-30 carbon atoms.) Pendant alkyl groups, especially lower alkyl groups, may be attached to the linear chains. However, branching of the diol alkyl chain reduces the load-carrying capacity of the diol lubricant, so it is preferred that there be no more than two pendant alkyl groups on C C chains, and no more than four pendant alkyl groups on C -C chains. The pendant groups should each contain no more than three carbon atoms.

Typical B-ketols which may be used in the lubricant composition of this invention include 4-n-dodecyl-2-ethanoylphenol, 4-n-hexadecyl-2-ethanoylphenol, 6-n-eicosyI-Z-ethanoylphenol, 4-n-pentacosyl-2-ethanoylphenol, 4-n-triacontyl-2-ethan0ylphenol, 4-n-octadecyl-2-propanoylphenol, 6-n-pentadecyl-Z-butanoylphenol, 4-n-heptadecyl-6-methyl-2-hexanoylphenol, 4-n-tridecyl-2- 3'-methylpentanoyl phenol,

4- 1 '-methylhexadecyl) -2-ethanoylphenol,

4-( 1,7'-dimethyleicosyl -6-methyl-2-ethanoylphenol, 4- 1 '-methyloctadecyl)-2-ethanoylphenol,

4-( 1'-methylpentacostyl) -2-ethanoylphenol,

4- 1 '-methyleicosyl) -2-pentanoylphenol,

4-( l',3',5',7'-tetramethyloctyl) -2-heptanoylphenol, 4-( 1', 1 0'-dimethyloctadecyl -2-ethanoylphenol, 6-(1'-methylpentadecyl)-2ethanoylphenol,

1 -hydroxy-'3 -n-p entadecanone, 1-hydroxy-3-n-eicosanone, 1-hydroxy-3-n-pentacosanone, 1-hydroxy-3-n-pentatriacontanone, 6-hyclroxy-8-n-pentacosanone, 3-hydroxymethyl-2-octadecanone, 3-hydroxymethyl-7-ethyl-9-methyl-2-eicosanone, 4-hydroxy-2-eicosanone, etc.

Mixtures of two or more of the above may also be used.

The alkylated Z-alkanoylphenols are prepared by first alkylating one of the phenolic compounds listed above, and then acylating the alkylated phenol to an ester with an anhydride. The ester is then isomerized to the 2-alkanoylphenol, by reaction in the presence of aluminum chloride. B-ketols in which the ,B-ketol function is not partially incorporated into an aromatic ring, can be produced by converting a l-olefin to a 1,2-epoxide, followed by isomerization of the epoxide to the corresponding 2-ketone, by-reaction in the presence of cobalt car 4 bonyl. The 2-ketone is then reacted with an aldehyde to produce a mixture of isomeric [i-ketols.

Besides their utility in the lubricants of this invention, the B-ketols find use as agents to stabilize polymers against ultraviolet radiation damage. The alkyl-substituted 2-alkanoyl phenols may also be expected to act in some applications as oxidation inhibitors.

The carrier fluid which comprises the major portion of the lubricant composition of this invention may be a refined hydrocarbon oil such as a refined mineral oil or a hydrocarbon distillate, a halogenated or oxygenated hydrocarbon, or water. The non-aqueous carrier fluids, particularly the hydrocarbon oils, serve both as carrier fluids for the fi-ketols and provide hydrodynamic lubrication themselves. Consequently, no additional lubricant is ordinarily needed when the carrier fluid is non-aqueous.

The carrier fluid will comprise the major portion of the composition. It will be present as 60 to 98 weight percent, preferably to 95 weight percent, of the composition. Non-aqueous carrier fluids will preferably be present as to weight percent of the composition, while in an aqueous composition the water will preferably comprise 80 to 95 weight percent. (All percentages herein are by weight based on the total composition as Percentage calculations are simplified herein by postulating that all components retain their individual identities in the final composition.)

Water is the preferred carrier fluid because of its good heat removal properties. However, since water itself provides little lubrication, it is generally preferred to add a hydrodynamic lubricant to the aqueous B-ketol system. Typical lubricants which are added in amounts of about 1 to 15 weight percent of the composition are hydrocarbon oils, particularly synthetic hydrocarbons such as polybutenes. The hydrodynamic lubricant should not itself stain the surface of the aluminum.

In the lubricant composition of this invention, the fi-ketol comprises a minor portion, no more than 30 percent by weight. Preferably, the fi-ketol comprises no more than 10 weight percent of the composition, with a minimum B-ketol concentration of 0.1 weight percent. The most preferred range of concentration is 0.1 to 5.0 weight percent. (Relative proportions of the components are selected such that the sum of the contents of the components is 100%.)

Since the ,B-ketols are essentially insoluble in water, they are incorporated into the water/fl-ketol system through the use of 0.1 to 10 weight percent, preferably 0.1 to 1 Weight percent, of an emulsifier. The emulsifier may be ionic or nonionic. Suitable emulsifiers include alkyl aryl polyethoxy alcohols, sorbitan monooleate, polyethoxylated amines, amides, or fatty acids, etc.

The refined hydrocarbon oils used as carried fluids in the non-aqueous lubricants of this invention are generally hydrocarbon oils produced by distillation, cracking, hydrogenation, or other refining processes. They typically have boiling points of 500-1000 F. and viscosities of 50500 SSU at 100 F. A typical example of a suitable oil is a hydrocarbon neutral oil having a viscosity of SSU at 100 F.

Halogenated and oxygenated hydrocarbons which are not significantly reactive with the fi-ketols or other components of the lubricants of this invention may also be used as carrier fluids. Suitable oxygenated hydrocarbon carrier fluids include carboxylic acid esters, alcohols, ketones, ethers, and aldehydes. Representative of these compounds are ethanol, methanol, isopropanol, acetone, methyl ethyl ketone, Z-hexanone, methyl isobutyl ketone, ethyl ether, n-propyl ether, ethyl phenyl ether, 1,4-dioxane, etc. The halogenated hydrocarbons include haloalkyl and haloaryls. Representative compounds include carbon tetrachloride, 1,l,1trichloroethane, chloroform, bromoform, 1,2-dichloroethane, chlorobenzene, etc. Carrier fluids may also have both oxygen and halogen components, as in the case of a halo ether.

The carrier fluid may, if desired, be a mixture of two or more of the above materials. All components must be mutually miscible or capable of being made so by the use of appropriate emulsifiers. The fi-ketol must, of course, also be miscible with the carrier fluid or, as in the case of water as a carrier fluid, capable of being made so by the use of an emulsifier.

The lubricant composition of this invention may also contain conventional additives, such as anti-rust agents and oxidation inhibitors. These must, of course, be compatible with the other components of the composition and, in particular, should not be reactive with the B-ketol. These additives when present will normally constitute about -25 weight percent of the lubricant composition.

Table I below illustrates the lubricating properties of the fl-ketol lubricants of this invention. The data in this table were derived from a Falex Machine test. This is a well known test in which a cylindrical shaft of steel is rotated between and in contact with two V-shaped aluminum blocks. The shaft is connected to a motor by a small shear pin. The shaft and blocks are immersed in the lubricant to be tested. An increasing load is then placed on the blocks, forcing them against the rotating shaft. The point at which the shaft seizes against the blocks and shears the pin is measured, and the force being exerted against the blocks at that point is recorded as the failure load of the lubricant.

TABLE I Falex machine Aqueous lubricants: failure load, lbs. Base lubricant 1 (avg) 1600 Base lubricant-l-Z parts by weight of:

(a) mixture of 4- and 6-(cw alkyl) 2 Z-ethanoylphenols 4000 (b) mixture of 4-methyl-6-(cw alkyl)- 2-ethanoylphenols 3500 (c) mixture of 4-(cw alkyl)-6-methyl- 2-ethanoylphenols 2250 (d) mixture of 1 hydroxy-3-n-C alkanones and 3-hydroxymethyl-2- n-C alkanones 4000 Non-aqueous lubricants:

Base lubricant (avg) 2400 Base lubricant+ parts by weight of a mixture of 4-methyl-6-(cw alkyl)-Z-ethanoylphenol 2850 The aqueous base lubricant consisted of a mixture of 90 parts by weight water, 7.6 parts by weight of a. polybutene having a number average molecular weight of about 330, and 0.4 part by weight of an emulsifier.

c\v alkyl" refers to a mixture of l-methylheptadeeyl, 1- methyloctadecyl, and l-methylnonadecyl radicals, derived from a commercial mixture of C1B-20 straight-chain l-olefins. Since these materials are not separated prior to allrylation of the phenol, the B-ketol end product will actually be a mixture of Bketols having different alkyl chain lengths.

3 The term 3-n-C1eio alkanones refers to a mixture of ketones derived from a mixture of C-1s 1olefins.

These compounds were derived from the same Cls-m l-olefin mixture of Note 3 above, and are isomers of th B-ketols of Note 3, having alkyl chains 1 carbon atom less in length than the respective Note 3 B-ketols.

{The nonaqueous base lubricant was a neutral oil having a viscosity of 480 SSU at 100 F.

It is evident from the data of Table I that lubricants containing B-ketols provide significantly higher degrees of lubrication of aluminum surfaces and substantially increase the load-carrying capacity of the aluminum surfaces. It is also seen that both aqueous and non-aqueous B-ketol lubricant compositions are superior aluminum lubricants.

The B-ketol lubricant compositions of this invention also substantially reduce wearing of aluminum surfaces. This is illustrated in Table II below. The data in Table II were derived from the Falex Machine test described above. Each lubricant was run in the Falex Machine test to its failure point, and the amount of wear of the blocks then measured as the milligrams of aluminum lost. Because the lubricants with the better load-carrying capacity will run longer in the test, they will be subject to the severest wearing conditions. Thus the diflerences between the poorer and better lubricants are emphasized.

In each example reported below in Table II, the base lubricant was the aqueous base lubricant described in Note 1 of Table I above, and each B-ketol was present as an additional 2 parts by weight. The Falex aluminum V-blOck wear, with the base lubricant alone, was 110 milligrams. The abbreviations of the components in Table II are the same as those described in the notes for Table I.

TABLE II Falex aluminum Wear re- V-block dnction, B-Ketol wear, mg. percent a. Mixture of 4- and 6-(cw alkyl)-2-ethano- 23 79 ylphenols. b Mixture of 4-methyl-6-(cw alkyl)-Z-eth- 28 75 anoylphenols. e Mixture of 4-(cw alkyl)-G-methyl-Z-eth- 31 72 anoylphenols. d Mixture of 1-hydroxy-3-n-Cw w alka- 10 91 nones and 3-hydroxymethyl-2n-C15- alkanones.

It is apparent from the data of Table II that the fi-ketol lubricants significantly reduce the wear on aluminum surfaces. The superiority of the 8-ketol lubricants is even more evident when one observes that they were subjected to longer Falex Machine runs than the base oil and yet gave substantially reduced Wear of the aluminum.

The B-ketol lubricants may also be used to lubricate metals other than aluminum. This is illustrated in Table III below. In each case the fi-ketol lubricant contained 95 parts of a hydrocarbon pale oil having a viscosity of 370 SSU at F. and 5 parts by weight of the fl-ketol. This was used to lubricate a cast-iron pin rubbing on a rotating chromium-plated disc in a Godfrey Tribometer. The load on the pin was 22 pounds and the speed of the rotating disc was 2.7 feet per minute. The apparatus was run for 30 minutes, and the volume of metal worn from the pin was measured. With the pale oil alone as the lubricant, 1.9 10- mm. of metal was removed. The abbreviations used in Table III are as defined in Table I above.

TABLE III Metal Wear reremoval, duction, B-Ketol 10- mm. percent a Mixture of l-hydroxy-ii-n-Om-m alkanones 1. 3 32 and 3-hydroxymethyl-2-n-Cis-is a1kanones. b Mixture of 4- and 6-(cw alkyl)-Z-ethanoyh 0. 4 76 phenols. c Mixture of 4-methyl-6-(cw alkyl)-Z-ethano- 0. 78 59 ylphenols.

These data illustrate the versatility of the [i-ketol lubricant compositions and further illustrate that the B-ketol lubricant compositions can provide good lubrication for any metal surface with which the B-ketol can coordinate.

The above description and data are intended only to be exemplary. It is evident that there are many compositions which will fall within the scope and spirit of this invention.

OHO

All

wherein R is an alkyl substituent containing a linear chain of from 8 to 30 carbon atoms in length and R is an alkyl group of from 1 to 7 carbon atoms. 2. The composition of claim 1, wherein said fl-ketol is of the formula:

3. The composition of claim 2, wherein one of said R R R and R contains said alkyl group of from 8 to 30 carbon atoms in length, and each of the remaining three of said R R R and R is hydrogen or lower alkyl of from 1 to 6 carbon atoms.

4. The composition of claim 1, wherein said p-ketol is of the formula:

5. The composition of claim 4, wherein said R is an alkyl substituent containing a linear chain of from 12 to 24 carbon atoms and is substituted with a methyl group at the 1-position.

6. The composition of claim 4, wherein said R is an alkyl group of from 1 to 3 carbon atoms.

7. The composition of claim 1, wherein said carrier fluid is water.

8. The composition of claim 7, further comprising 1-15 weight percent of a hydrocarbon oil hydrodynamic lubricant.

References Cited UNITED STATES PATENTS 2,335,434 11/1943 Morey 252-54 3,282,842 11/1966 Bonner 252-52 R DANIEL E. WYMAN, Primary Examiner W. H. CANNON, Assistant Examiner US. Cl. X.R. 

